RustでHTMLをパースし，編集し，書き出す (html5ever)

html5ever_edit.rs

use std::cell::RefCell;
use std::rc::Rc;

use html5ever::{Attribute, LocalName, QualName};
use html5ever::driver::ParseOpts;
use html5ever::{local_name, ns, namespace_url};
use html5ever::{parse_document, parse_fragment};
use html5ever::rcdom::{Handle, Node, NodeData, RcDom};
use html5ever::serialize;
use html5ever::serialize::SerializeOpts;
use html5ever::tendril::{TendrilSink, StrTendril};

fn search_iter(node: &Handle) {
  match node.data {
    NodeData::Text { ref contents } => {
      println!("{}", contents.borrow().to_string() );
    },
    NodeData::Element { ref name, ref attrs, .. } => {
    },
    NodeData::Document { .. } => {
    },
    NodeData::Doctype { .. } => {
    },
    NodeData::Comment { .. } => {
    },
    NodeData::ProcessingInstruction { .. } => {
    },
  };
  for child in node.children.borrow().iter() {
    search_iter(&child);
  }
}

fn create_text_node(s: &str) -> Rc<Node> {
  Node::new(NodeData::Text {
    contents: RefCell::new(s.into()),
  })
}

fn create_element_node(
    name: QualName,
    attrs: Vec<Attribute>) -> Rc<Node> {
  Node::new(NodeData::Element {
    name: name,
    attrs: RefCell::new(attrs),
    template_contents: None,
    mathml_annotation_xml_integration_point: false,
  })
}

fn create_tag_name(name: &str) -> QualName {
  QualName::new(None, ns!(html), LocalName::from(name))
}

fn create_attribute(name: &str, value: &str) -> Attribute {
  Attribute {
    name: QualName::new(None, ns!(), LocalName::from(name)),
    value: StrTendril::from(value),
  }
}

fn main() {
  let html_data = "これは<span>テスト</span>です。";

  // let parser = parse_document(RcDom::default(), ParseOpts::default());
  // let dom = parser.one(html_data);

  let parser = parse_fragment(
    RcDom::default(),
    ParseOpts::default(),
    QualName::new(None, ns!(html), local_name!("body")),
    vec![],
  );
  let dom = parser.one(html_data);

  search_iter(&dom.document.children.borrow()[0]);

  let html_node = &dom.document.children.borrow()[0];
  let span_node = &html_node.children.borrow()[1];
  let a_node = create_element_node(create_tag_name("a"), vec![]);
  a_node.children.borrow_mut().push(create_text_node("アンカー"));
  span_node.children.borrow_mut()[0] = a_node;

  if let NodeData::Element { ref attrs, .. } = span_node.data {
    attrs.borrow_mut().push(create_attribute("style", "color: #ff0000"));
  }

  let mut bytes = vec![];
  // serialize(&mut bytes, &dom.document, SerializeOpts::default()).unwrap();
  serialize(&mut bytes, &dom.document.children.borrow()[0], SerializeOpts::default()).unwrap();
  println!("{}", String::from_utf8(bytes).unwrap());
}